Hydraulic air-conditioning on 400 series Cessna's

[18-Wheeler]

I was told that the air-conditioning compressor on the Cessna piston twins was hydraulically driven, is that right?
If so, does anyone have any photos or diagrams of them please? And how efficient is the drive system?

[411A]

Some are hydraulic, some electric...depends on the specific system installation.
The hydraulic driven A-C systems are very efficient, in my experience.
Cold cold air if properly serviced.